Is the file crashing on open, or, more likely, are you having trouble selecting the file? Is it grayed out in the file selection list? If the latter, then are you using Mac OS file dialogs? I.e. When you select "Load Game" or "Save Game" does the Civ3 software drop into the background and show you a normal Mac OS File Open dialog, or does it show you a Civ3 File Open? You set this option in the first screen that comes up when you launch Civ3.
To remove this issue with PC files, you can change the option to use the Civ3 file dialogs instead.
If you prefer to use Mac OS ones (I do) then you need to make sure that the file type and creator are set correctly. These are extra bits of information that were required for old Mac OS 9 file management, and are still supported in OS X for backwards compatibility. Unfortunately the Civ3 file system assumes you are using OS 9 and therefore looks for this data. A bug (/feature?) in the 1.29b2 software also means the file extension must be upper case - .SAV, not .sav - but you've done that OK.
You can ensure that this data is included (and also make sure that the .SAV is upper case) by attaching the Civ3 File Fixer Applescript, linked in my signature, to your saves folder as a Folder Action. Any .sav or .SAV file that you put into the folder will then be edited automagically to make it work. Or you can drag and drop a file or folder onto the script to have it update the file(s).
on my Mac. I shortened the name and changed the "Open With" but no joy. Hopefully, the .SAV is attached.
. I then dropped the save file on your Applescript and it indeed fixed the file. 
Now it opens even with "MacOS dialogs". Thanks.
